This museum was invented in a novel before being made real by the author.

A Turkish monastery tucked into a cliff wall.

This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Hidden beneath the streets of London is a secret subway that only carried mail.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

France's most famous cemetery, with some of its most curious tombs.

This historic black and white monastery is one of Bulgaria's architectural jewels.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

An abandoned saucer-shaped monument in the Bulgarian mountains.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

One of the largest Chinese cemeteries outside of China spent years overgrown and forgotten.

Tracking the 1,500-year history of Korea's star cabbage.

Numerical symbolism abound at East Asia's oldest observatory.

Only the foundation remains of the rest stop building that was hit by three large tsunami waves, killing 47 visitors.

According to Hindu belief, this shallow island chain was created by a god with an army of monkeys.

Huge herds of Asian elephants can be seen walking, bathing, and just chilling at this Sri Lankan park.

Surat Thani's official flower—and the world's largest—smells of rotting meat.